A drug has shown promising signs of fighting a range of cancers in early trials, London-based scientists say.

Institute of Cancer Research scientists found the drug 17AAG blocked breast, bowel, skin and prostate cancer in 30 patients as well as in the laboratory.

The Journal of Clinical Oncology study confirms 17AAG works, but more trials are needed before the prototype becomes a real treatment option, experts say.

The drug works by targeting a molecule that is important for tumour growth.

The multi-pronged attack by this drug shows promise in treating a range of cancers

Professor Peter Rigby of the Institute for Cancer Research

The molecule, heat shock protein (Hsp) 90, relays messages around cells by helping to control the structure and function of a large number of other molecules that are critical for cancer growth.

Without these molecules cancer cells die, whereas healthy cells are not affected by their loss.

This makes the new drug highly targeted, said the team from the Royal Marsden Hospital in London.

Also, because it targets so many different features of cancer's machinery all at once, it should make it much more difficult for tumours to develop resistance to treatment, experts said.

Multi-pronged attack

Lead researcher Professor Paul Workman explained: "By blocking the action of Hsp90, the drug has the potential to attack cancer by shutting down a range of systems that cancer cells use to spread and grow."

With funding from Cancer Research UK, they tested the drug in 30 patients with advanced cancers.

Following the good results, they now plan more trials, each looking at patients with a specific tumour type, to establish how well it works for different cancers.

Professor Peter Rigby, chief executive of the Institute for Cancer Research, said: "Although further trials need to be conducted, early indications suggest that the multi-pronged attack by this drug shows promise in treating a range of cancers."

Bill Greenhalf, a lecturer in molecular biology at the University of Liverpool, which has also been investigating drugs that target Hsp90, said: "This is a prototype drug.

"There are more derivatives available. Those are going into trials on their own and in combination with other drugs and that is very exciting.